Duct tape, parachute cord, and cable ties. We carry a boat full of tools and spare parts, but these three make every sailors list of indispensables for temporary repairs. We’ve reviewed conventional duct tape (If you Cant Duct it, Tough Duct it, Practical Sailor, December 2009), self-bonding tapes (Atomic Tape, PS, December 2005), and gaffers tape, but somehow skipped over foil duct tape. It does a few things ordinary duct tape just can’t.
Sealing Stink. While testing sanitation hoses (Marine Sanitation Hose Test, PS April 2013) we learned that a wrapping of foil tape reliably blocked odor. While not the preferred cure for failing hoses, gases simply can’t go through metal, no matter how thin. This is why Mylar balloons stay inflated for months-a mere 0.5 micron aluminum coating is all that is needed to render the plastic impermeable to the smallest of gas molecules-helium.
Sealing Paint Cans. A tightly sealed lid is best, but if the rim is dented or gummed-up, or if you simply want a little extra protection for your $200-per-gallon bottom paint, a tight wrap of foil duct tape will retain the solvents just as securely as a factory seal. Solvents go through vinyl duct tape.
Ducts. Conventional tape is superior where you need some stretch-sealing the cover of an insulated flexible AC duct to an outlet fitting, for example. But when fabricating the ducts themselves and sealing flanges between sections, rigid non-stretch support and complete impermeability to moisture are better. Quality aluminum tape is a permanent solution.
Because it is non-stretch, it is most effective on smooth and regular surfaces, where it can be applied carefully and without wrinkles. For sealing cans, wrap the rim smoothly, and then bend it over while circling in one direction.
Maybe you don’t need to keep this one on the boat, but it should certainly be in your tool bag at home.